Carburation agitator



I' March 11, 1958 E. A,IBLQMBE RG 2,826,183

. CARBURAT-ION AGITATOR Filed Aug. 27, 195e l 2 sheets-sheet 1 INVENTOFZ Ey M Wy United States Patent CARBURATION AGITATOR Eero A. Blomberg, Copper Clii, Ontario, Canada Application August 27, 1956, Serial No. 606,291 7 claims. (ci. 12s-133) My invention relates generally to internal combustion engines.

More particularly the invention is concerned with improvements in Carburation arrangements for supplying the appropriate explosive mixture of fuel to the intake parts of an internal combustion engine.

Although internal combustion engines of many types have been widely used for many years, it is generally accepted as a fact that the known arrangements for supplying the basic fuel and air mixture to the combustion chambers of the engine leave very much to be desired.

One of the problems not heretofore solved is to provide a carbureter arrangement which does not waste fuel. Engines are required to operate over a very rapidly and widely changing range of temperatures. Itis also true that an internal combustion engine will supply a reasonably acceptable power capability over a rather wide range of fuel and air mixtures, but is not an a-cceptably eiiicient prime mover unless the mixture is maintained at a substantially correct ratio. For example, a conventional known make of passenger motorrcar may perform with an average efficiency represented by miles per gallon of consumed basic fuel under certain specified conditions of speed, external (weather) temperature and under-the-hood temperature. A change to higher or lower temperatures will often change the elciency of the same vehicle to a gure as low as l0 miles per gallon. Yet the operator of the vehicle may be scarcely conscious of any difference in the apparent performance of the engine and such difference may only be obvious on a check of fuel consumption.

Much effort has been expanded to correct this condition with the result that so called modern carbureters are observed, typically, to include a complex assortment of expensive-to-make jets, low and high speed needle valves variable pitch throttles, thermally controlled choke vanes with additional linkages to accelerator controls and to engine main shaft, primary and secondary vaporizing chambers and the like. Yet, withal, these complex arrangements are still far from achieving the goals sought, to wit, economy of fuel consumption. l

It is a main object lof this invention to provide a carbureter arrangement of simple and low-cost design which greatly improves the fuel efficiency of an internal cornbustion prime mover over a wide range of operating temperatures and speeds.

lt is a further object to provide an improved carbureter arrangement of the capability indicated which is easy to initially adjust and which will automatically maintain a high fuel economy without requiring the fixed adjustments to be constantly revised when operating conditions change within a seasonal range.

These and other objects are achieved according `to my invention by providing an arrangement wherein the fuel local reservoir is positioned so as to be kept relatively cool and wherein the vapor generator is provided with a heat concentrator so arranged that the temperature of the air supplied to the vaporizer is always so much higher than the highest ambient temperature in the engine enice vironment that the difference between these temperatures is always large and is relatively of constant value after the irst few minutes of engine operation.

These and other objects of my invention will `become apparent from the following description of a typical construction in accordance with my discoveries, the text being taken in conjunction with the attached drawings wherein:

Figure l is a plan view looking down upon the top of a super heated carbureter arrangement' in accordance with my invention.

Figure 2 is a side elevation of a carburetor arrangement in accordance with my invention and is shown in position upon the side of an internal combustion engine, the co-operating part of the said engine being envisaged in the showing, and the fuel bowl being omitted from the view to show other portions of the arrangement more clearly.

Figure 3 is a vertical sectional view through Figure l.

Figure 4 is a cross sectional view along the line 4--4 of Figure l and shows details of the relationships involving the cool reservoir and the super-heated vapor tube.

In the drawings in which all similar parts carry identical reference numerals 1 is an intake manifold of the engine and 14 is an exhaust manifold. These manifolds are respectively connected by ducts 2, 3, 4 to the intake parts of the engine 8, and by ducts 5, 6, 7 to the exhaust parts thereof. f

Clamped in good heat conductive contact with the exhaust manifol-d is an air intake duct 9 which receives air from air cleaner 1i). Part of the air from duct 9 traverses the length of duct 9 and passes into the top of a vapor tube 11 under the control of choke valve 12 (Figure 4). Another part of the air from the air strainer 10 enters super heater tube 13 which is positioned within the exhaust manifold 14 and extends from end to end thereof. One end extends through the corresponding end wall of the exhaust manifold and is open to the duct 9 to receive air from strainer 10. The other end is returned bent to a point over the vapor tube 11 where it is turn-ed down and passes through the wall of the exhaust manifold into the central region of the vapor tube 11. The orice 15 of this tube is constricted to form a nozzle and at the stricture a duct 16 is positioned to deliver basic fuel from a reservoir 17 which is a float chamber in which a supply of fuel is maintained at a constant level by an ordinary float 27 belonging to a needle valve in a supply line. Duct tube 16 is desirably fitted with an adjustable valve 16 which is thermostatically controlled and `devised to be fully onen when the engine is cold.

The lower end of the vapor tube communicates with the intake manifold 1 under control of a throttle valve 18.

It will be evident that when the engine establishes a vapor attenuation or so-called vacuum in the manifold 1 air will be sucked through the vapor tube 11 along two paths; one path will be the super-heater tube 13; the other will be the duct 9. By presetting the choke 12 the ratio of super-heated to mildly heated air can be precisely determined.

As the air is sucked, very hot, through the tube 13 and whistles past the fuel supply tube 16, fuel is drawn into the venturi nozzle 15 and is instantly vaporised and mixed with very hot air so that it passes into the manifold and to the intake ports 2, 3, 4, without having time to cool sufficiently to condense and is therefore a highly comminuted mixture of fuel and air when it enters the engine cylinder. The cylinder being already very hot (after a few cycles of combustion have occurred) no condensation occurs, the gas mixture loses no heat and there is no condensation on the cylinder mechanism and therefore no oil dilution by raw fuel. Furthermore, there being no low temperature or partly fogged fuel in the system the gas stage is maintained through the compression cycle and combustion eiciency is high.

The fuel reservoir 17 is positioned outside the hot region of the system and is supported by relatively low conductivity members 19, 20, and mostly surrounded by air so that it remains relatively cool. This arrangement inhibits evaporation of the fuel and so removes a common source of fuel loss which characterises systems wherein the reservoir for fuel is in the hot-engine environment.

Refinements in the system worth noting are the choke air or pressure relief tube 21 and the idling by pass bleeder tube 22. This latter tube is made small enough in bore so that the capillary effect of the liquid is suiicient to prevent loss of fuel when the engine is at rest, but will yield fuel to the vacuum at 23 when the engine is idling on a closed throttle 18.

An important feature 'resides in the small air by-pass holes 24, Vwhich allow a predetermined amount of exhaust gas from exhaust manifold 14 to enter the air duct of the super heater tube 13; this prevents ignition of fuel in the tube 13 which sometimes backs up from the nozzle 1S under certain conditions encountered in engine operation, such for example as leaky valve seals or back-fires, or a high temperature condition.

In the embodiment shown, the superheater 13 and vapor tube 11 with its accessories are incorporated in a mutually planned assembly including the intake and exhaust manifolds whose communication ducts 2, 3, 4, and 5, 6, 7 are attached Vto the side wall 25 of engine 8 in conventional manner.

The cool fuel reservoir may receive fuel from line connection '26 and the level of fuel may be regulated by said float 27 operating a control valve in the delivery line (not shown) as will be well understood in the art.

This embodiment represents a presently preferred arrangement but does not limit the construction to that form. Any arrangement which includes the cool reservoir and superheated vapor chamber may be arranged in accordance with my teachings. Any and all such arrangements so organised should be considered to lie within the ambit of my appended claims.

What I claim is:

l. In combination with an engine having a fuel input manifold and a hot gas exhaust manifold, a carbureter arrangement comprising a separate fuel reservoir positioned to reside in a relatively cool region of the engine environment, a vapor tube positioned adjacent a relatively warm region of the engine environment and characterised by an intake facility including an air intake control valve and an output facility including an output control valve, a first air intake duct positioned in thermal contact with said hot gas exhaust manifold over a porvtion of its length and connected to supply air to the intake facility of said Vapor tube, a second air intake duethaving an input end positioned to receive air from said 'first air input duct, a medial portion positioned to reside within the main portion of said hot gas exhaust manifold in such attitude as to present a substantially large heat conductive surface in thermal contact with hot gasses passing outwardly through said exhaust manifold and an air delivery portion positioned to reside within said Vapor tube and characterised by a delivery nozzle directed toward the output facility of said vapor tube, duct means for transmitting fuel from said reservoir to the interior of said second air duct at a point adjacent said nozzle, and means for delivering a fuel and air mixture from the output facility of said vapor tube to the fuel input manifold of the engine.

2. An arrangement as defined in claim l including an air relief duct connecting the top portion of said fuel reservoir and said rst air intake duct.

3. An arrangement as defined in claim l including a capillary tube positioned and dimensioned to connect the fuel occupied portion of said reservoir to the fuel intake region of said intake manifold, said tube being characterised in that its capillary action prevents the flow of fuel therein when the .air pressure in the intake manifold is of the order of that in the engine environment.

4. A construction according to claim l wherein the said second air intake duct is characterized along its length by a predetermined number of apertures dimensioned to admit a specified amount of the engine combustion product into the interior of said air intake duct.

5. The combination with the intake and exhaust manifolds of an internal combustion engine, of a vapor tube vertically arranged in close proximity to said manifolds,

said vapor tube having an upper inlet end for air and a lower outlet end for a fuel mixture, a venturi nozzle in said vapor tube, a float chamber forming a fuel reservoir and connected to a source of liquid fuel supply, a duct tube extending from said float chamber and passing through the wall portion of said vapor tube and into said venturi nozzle, an air intake duct extending along said exhaust manifold in heat conductive contact therewith for heating air, said air intake duct having an air admitting opening for connection with an air strainer and also having a delivery opening, said delivery opening being connected to said upper inlet end of said vapor tube, a super heater tube disposed within said exhaust manifold and extending lengthwise thereof with an admitting end leading through a wall portion of said exhaust manifold in close proximity to said air admitting opening of said air intake duct for intake of air therefrom, the other end of said super heating tube being connected to said venturi nozzle, said super heater tube having an -opening in its wall within said exhaust manifold and valve means for control of said vapor tube.

6. A carbureter arrangement comprising a separate fuel reservoir, a vapor tube characterised by an intake facility including an air intake control valve and an output facility including an output control valve, a first air intake duct connected to supply air to the intake facility of said vapor tube, a second air intake duct having its air delivery and positioned within said vapor tube and characterised by a nozzle directed toward the output facility of said vapor tube, means for transmitting fuel from said reser- Voir to the interior of said second air intake duct at a point adjacent said nozzle, and means for rapidly and continuously heating the air in ysaid second air intake duct, the aforesaid structure being characterised by the provision `of a pressure relief duct interconnecting said first air intake duct and the upper region of said fuel reservoir.

7. A carbureter arrangement comprising a separate fuel reservoir, a vapor tube characterised by an intake facility including an air intake control valve and an output facility including an `output control valve, a first air intake duct connected to supply air to the intake facility of said vapor tube, a second air intake duct having its air delivery end positioned within said vapor tube and characterised by a nozzle directed toward the output facility of said vapor tube, means for transmitting fuel from said reservoir to the interior of said second air intake duct at a point adjacent said nozzle, and means for rapidly and continuously heating the air in ysaid second air intake duct, the aforesaid structure being characterised by the pro- Vision of a capillary tube positioned to communicate fuel from said reservoir to the output facility `of said vapor tube `on the delivery side of said output control valve.

References Cited in the le of this patent UNITED STATES PATENTS 

